Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=false, destructiveHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral fact beyond the annotations — that the call returns the saved record including its SyncToken, which matters for chaining into update_estimate. It says nothing about validation failures, required entity fields, or duplicate handling.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences, the action is front-loaded, and the return-shape note is the only second-sentence content. Nothing is redundant with the name or schema.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description usefully compensates by stating what comes back (saved record + SyncToken). The entity and company semantics are fully covered in the schema, so the main remaining gap is error/precondition behavior, which is minor for a straightforward create.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%: entity is documented as a QBO API v3 Estimate object with an explicit PII warning, and company explains the multi-company fallback. The description contributes no additional parameter meaning, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ("Create an estimate") scoped to QuickBooks Online, which cleanly separates it from get_estimate, search_estimates and update_estimate. It does not, however, explicitly name any sibling or contrast itself with them, so the differentiation comes only from the verb.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as update_estimate when the record already exists. An agent can infer 'this creates a new estimate' from the name, but the description adds nothing to that inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.